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AP Biology The Building Blocks 3.3 Nucleic Acids
25

The Building Blocks

Jan 08, 2016

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The Building Blocks. 3.3 Nucleic Acids. HELIXHELIX. Nucleic Acids. Information storage. Nucleic Acids. Function: store & transmit hereditary information Examples: RNA (ribonucleic acid) DNA (deoxyribonucleic acid) Structure: monomers = nucleotides. Nucleotides. 3 parts - PowerPoint PPT Presentation
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Page 1: The Building Blocks

AP Biology

The Building Blocks 3.3 Nucleic Acids

Page 2: The Building Blocks

AP Biology

HELIXHELIXHELIXHELIX

Page 3: The Building Blocks

AP Biology 2006-2007

Nucleic AcidsInformation

storage

Page 4: The Building Blocks

AP Biology

Nucleic Acids Function:

store & transmit hereditary information

Examples: RNA (ribonucleic acid) DNA (deoxyribonucleic acid)

Structure: monomers = nucleotides

Page 5: The Building Blocks

AP Biology

Nucleotides 3 parts

nitrogen base (C-N ring) pentose sugar (5C)

ribose in RNA deoxyribose in DNA

phosphate (PO4) group

Are nucleic acidscharged molecules?

Page 6: The Building Blocks

AP Biology

RNA & DNA RNA

single nucleotide chain

DNA double nucleotide chain

N bases bond in pairs across chains

spiraled in a double helix double helix 1st proposed as structure of DNA

in 1953 by James Watson & Francis Crick (just celebrated 60th anniversary in 2013!)

Page 7: The Building Blocks

AP Biology

Types of nucleotides 2 types of nucleotides

different nitrogen bases purines

double ring N base adenine (A) guanine (G)

pyrimidines single ring N base cytosine (C) thymine (T) uracil (U)

Page 8: The Building Blocks

AP Biology

Building the polymer

Page 9: The Building Blocks

AP Biology

Nucleic polymer Backbone

sugar to PO4 bond phosphodiester bond

new base added to sugar of previous base

polymer grows in one direction N bases hang off the

sugar-phosphate backbone

Dangling bases?Why is this important?

Page 10: The Building Blocks

AP Biology

Pairing of nucleotides Nucleotides bond between

DNA strands H bonds purine :: pyrimidine A :: T

2 H bonds G :: C

3 H bonds

Matching bases?Why is this important?

Page 11: The Building Blocks

AP Biology

Information polymer Function

series of bases encodes information like the letters of a book

stored information is passed from parent to offspring need to copy accurately

stored information = genes genetic information

Passing on information?Why is this important?

Page 12: The Building Blocks

AP Biology

AA

A

A

TC

G

CG

TG

C

T

Page 13: The Building Blocks

AP Biology

DNA molecule Double helix

H bonds between bases join the 2 strands A :: T C :: G

H bonds?Why is this important?

Page 14: The Building Blocks

AP Biology

Copying DNA Replication

2 strands of DNA helix are complementary have one, can build other have one, can rebuild the

whole

Matching halves?Why is this

a good system?

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AP Biology

When does a cell copy DNA? When in the life of a cell does DNA have

to be copied? cell reproduction

mitosis gamete production

meiosis

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DNA replication“It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”

James WatsonFrancis Crick

1953

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AP Biology

Watson and Crick … and others…1953 | 1962

Page 18: The Building Blocks

AP Biology

Maurice Wilkins… and…1953 | 1962

Page 19: The Building Blocks

AP Biology

Rosalind Franklin (1920-1958)

Page 20: The Building Blocks

AP Biology

Interesting note… Ratio of A-T::G-C

affects stability of DNA molecule 2 H bonds vs. 3 H bonds biotech procedures

more G-C = need higher T° to separate strands

high T° organisms many G-C

parasites many A-T (don’t know why)

Page 21: The Building Blocks

AP Biology 2006-2007

Macromolecule Review

Page 22: The Building Blocks

AP Biology

Carbohydrates Structure / monomer

monosaccharide

Function energy raw materials energy storage structural compounds

Examples glucose, starch, cellulose, glycogen

glycosidic bond

Page 23: The Building Blocks

AP Biology

Lipids Structure / building block

glycerol, fatty acid, cholesterol, H-C chains

Function energy storage membranes hormones

Examples fat, phospholipids, steroids

ester bond (in a fat)

Page 24: The Building Blocks

AP Biology

Proteins Structure / monomer

amino acids levels of structure

Function enzymes defense transport structure signals receptors

Examples digestive enzymes, membrane

channels, insulin hormone, actin

peptide bond

Page 25: The Building Blocks

AP Biology

Nucleic acids Structure / monomer

nucleotide

Function information storage

& transfer

Examples DNA, RNA

phosphodiester bond